Samples, in particular tissue samples to be examined using a microscope, are routinely stained using staining devices, so that structures of the samples can be better seen in the microscopic image than in the case of unstained samples. For sample staining, a staining device includes two or more containers in which identical, similar or different process media are stored. The samples to be stained are immersed in the process media, where they remain for residence times which are dependent on the process step, the process medium, and on the sample to be stained. Once the predetermined residence time has elapsed, the samples are withdrawn from the container and transferred to the next container by means of a transport system. Depending on the staining method and/or the sample, the samples are in this manner successively immersed in a plurality of containers filled with process media. Moreover, the samples may be dried before, between or after the aforementioned steps, using an oven. For example, moist sections of paraffin-embedded tissue samples placed on slides may be dried in the oven, thereby evaporating the moisture and partially melting the paraffin, which improves the adherence of the tissue samples to the slides.
The containers and the oven, if provided, are positioned within the staining device during assembly thereof. After that, the containers and/or the oven may be replaced, for example, for purposes of repair. Moreover, optional components, such as the oven, cuvettes, or additional containers, may be added later. Further, the transport device, its attachment and suspension arrangement, as well as a lifting device of the transport device have manufacturing tolerances. In order for the staining operation to function properly after replacement or installation of components and despite the tolerances, the staining device is calibrated. During calibration, the exact positions of the containers and the oven in the staining device are determined, taking into account the tolerances, and stored in a processing unit. The staining process and, in particular, the transport system of the staining device can then be controlled by the processing unit.